Tanner crab Chionocetes bairdi Rathbun haemocyte classification and an evaluation of using differential counts to measure infection with a fungal disease

Abstract. The circulating haemocytes of the tanner crab, Chionocetes bairdi , were studied and classified as hyalinocytes, intermediate granulocytes and eosinophilic granulocytes. Differential haemocyte counts of normal crabs and crabs infected with an apparently pathogenic unnamed ascomycete fungus revealed a shift in the hyalinocyte-granulocyte ratio in infected crabs. There was a highly significant increase in the percentage of granulocytes and a corresponding decrease in hyalinocytes in infected crabs. This shift was thought to be caused by a marked increase in the relative number of eosinophilic gianulocytes. There was also a highly significant statistical relationship between the severity of the internal fungus infection, established by histopathological analysis of the major organ systems, and the increased number of circulating eosinophilic granulocytes. The results of the study indicate that differential haemocyte counts may be a valuable tool in monitoring the health of C. bairdi populations.     

Thin layer chromatographic determination of citrinin.

A thin layer chromatographic (TLC) method is described for the determination of citrinin in feeds. Citrinin is extracted from feed with methanol and water, the mixture is made alkaline with 10% sodium carbonate, and the aqueous solution is filtered and extracted with chloroform to remove most of the interfering materials. The aqueous layer is acidified with 2N HCl and extracted with chloroform. The chloroform extract is concentrated and spotted on a thin layer chromatographic (TLC) plate which is developed in chloroform-acetone-ethanol-water (60 + 40 + 10 + 1). The citrinin is viewed under ultraviolet light after TLC. Either visual or fluorodensitometric quantitation is used. Recoveries of citrinin from various feed samples spiked at levels of 2.0--5 micrograms/g were 75--92%. The proposed method can detect 0.5 micrograms/g feed, including corn, silage, ready mixed feeds, and feed pellets.     

DC polarography of cephradine and its application to capsules.

A polarographic method has been developed for the quantitative analysis of cephradine and its dosage forms. Direct determinations on capsules are carried out; excipients and coloring matter do not interfere in the determination. The electroactive product is formed by acidic hydrolysis with 5.0N HCl and heating at 80 degrees C for 60 min. Two polarographic waves are obtained: I = -0.46 V and II = -0.78 v vs. SCE. Both reduction waves are diffusion controlled. Wave I is preferred for analytical purposes. The precise chemical identity of the electroactive product has not been determined, but UV spectral data and the TLC Rf value are reported. A linear relation is established for levels of cephradine between 10(-2) and 10(-5)M in 5.0N HCl.     

Degradation of ioxynil by a soil fungus, Fusarium solani

A fungus, Fusarium solani, isolated from the soil, degraded ioxynil (3,5-diiodo-4-hydroxyben-zonitrile) in pure culture into at least eight products. Five products were detected in the organic fractions extracted from a culture grown in [¹⁴C]cyano-labeled ioxynil. Three additional products were separated by ion-exchange chromatography of the acidified aqueous phase. Cultures grown in the presence of [¹⁴C]ring-labeled ioxynil produced the same products in the organic extract and four to five products in the aqueous phase. The cyano-carbon of ioxynil was released as CO₂ at a faster rate than that of ring-carbons and was released after the initial ring cleavage. Two of the metabolites were identified as 3,5-diiodo-4-hydroxybenzamide and 3,5-diiodo-4-hydroxybenzoic acid.     

A method for measuring adenosine triphosphate in soil

A method was devised for the extraction and measurement of adenosine 5'-triphosphate (ATP) in soil that minimizes sorption of ATP on the soil colloids. Soil was ultrasonified for 1 min with a solution containing trichloracetic acid (0.5 m). disodium hydrogen orthophosphate (0.25 m) and paraquat dichloride (0.1 m). The ATP content of the filtered extract was determined without further treatment in a scintillation spectrometer by the firefly luciferin-luciferase system. Recovery of added ATP was greater using the extratant containing trichloracetic acid, orthophosphate and paraquat than with trichloracetic acid alone or with a sulphuric acid extradant. Recoveries of added ATP ranged from 45% to 84% in thirteen different soils; ATP contents from 0.64 to 9.03 μg g^?1 soil.     

Interactions between bacteria and ectomycorrhizal fungi

Interactions between eight ectomycorrhizal fungi and eight bacteria were tested on five laboratory media and in the rhizoplane of Pinus radiata. Depression of growth of the fungi by the bacteria in laboratory media was dependent on the medium and bore little relation to effects in the rhizoplane. In the rhizoplane, different bacteria could depress, have no effect or even stimulate growth of mycorrhizal fungi. Competition and antagonism are suggested as mechanisms for depression of the fungi. Some bacteria gave protection against the depressive effects of other bacteria. Considerable differences occurred between ectomycorrhizal fungi in their colonization of the rhizoplane in the absence of bacteria and also in their presence. The common mycorrhizal fungi Rhizopogon luteolus and Thelephora terrestris generally colonized roots well but the strain of Pisolithus tinctorius studied colonized poorly. Direct microscopy showed the percentage cover of the root by microorganisms was usually only 10–20%.It is proposed that interactions of ectomycorrhizal fungi with soil organisms are important in determining the successful introduction and persistence of inoculated ectomycorrhizal fungi. Fungi should be selected for compatibility with a wide range of soil microflora as well as efficiency in plant stimulation.     

Distribution and partial characterisation of acid hydrolysable organic nitrogen in six New Zealand soils

Six New Zealand topsoils of widely different origins and properties were subjected to 6m HC1 hydrolysis and the distribution of N fractions and amino acids were determined qualitatively and quantitatively.Of the total-N in the soils studied 83–91%, was hydrolysable with 6m HCl. The largest proportion of the hydrolysable N was α-amino acid N (38– 42%). followed by hydrolysable-unknown N (HUN) (14–24%), and NH₄⁺-N (14–22%). A significant proportion (25–50%) of the HUN fraction was accounted for by the non α-amino acid-N. Oxidative (3% H₂O₂) hydrolysis released N-phenoxy amino acid-N and possibly N-compounds which were complexed with phenols and sugars. All soils had a similar amino-acid composition with a predominance of acidic amino-acids.     

Colonization by Rhizobia of the seed and roots of legumes in relation to exudation of phenolics

A study of the colonization pattern of Rhizobium inoculated either in the soil or on to the seeds of green gram (Phaseolus aureus Roxb.), black gram (P. mungo L.) and sun hemp (Crotalaria juncea L.) revealed a significant reduction of Rhizobium in the spermosphere of sun hemp which was attributed to excretion of phenolic compounds by the seed. As the plants aged, the quantity of phenolics exuded by the roots was reduced and there was a parallel increase in the Rhizobium population in the rhizospheres of the three plant species.     

The evaluation of piromidic acid as an antibiotic in fish: an in vitro and in vivo study

Abstract. The activity of piromidic acid (PA, 8-ethyl-5, 8-dihydro-5-oxo-2-prior lidinopyrido [2,3–d] pyrimidine-6-carboxylic acid) against bacteria in fish was evaluated in vitro and in vivo .
In vitro , PA was effective against a wide range of pathogenic bacteria stocked in this laboratory and freshly isolated from fish. PA was active against organisms showing multiple drug-resistance and showed no cross-resistance to chloramphenicol, tetracycline and sulfamonomethoxine.
In vivo , orally administered PA was effective against experimental infections with Aeromonas hydrophila and Vibrio spp. in goldfish and eels. The efficacy of PA against these infections was equal to or higher than that of chloramphenicol, and higher than that of tetracycline. Distribution of PA in the Ash was investigated by bioassay and autoradiography. In the bioassay, orally administered PA was easily absorbed and distributed in the blood and tissues of major organs within 1 h after the administration. Peak levels were attained 2 to 4 h post dosing, and no residue was detected in the blood and tissues 48 h post dosing. The results obtained from the autoradiographic investigation in goldfish were similar to those from the bioassay. Therapeutic levels of PA were well tolerated by fish when administered with feed.     

Cellular immune response in rainbow trout Salmo gairdneri Richardson to Yersinia ruckeri O-antigen monitored by the passive haemolytic plaque assay test

Abstract. The specificity and kinetics of the immune response of rainbow trout ( Salmo gairdneri ) to single injections of an O-antigen extracted from the bacterial pathogen Yersinia ruckeri , which causes enteric redmouth in fish, were investigated by the passive haemolytic plaque assay and serum antibody quantitation. Doses ranging from 5 ng to 500 mg in 10-fold increments were injected intraperitoneally into groups of trout held at 17 × 1°5°C. The occurrence of plaque forming cells (PFC) and humoral antibody was followed for 35 days after injection. Trout gave an immune response to doses of 500 ng and above. Seven days after injection no humoral antibody was detected, but PFC were found in the spleen. The maximum PFC numbers occurred 11 days after injection. On day 21, few PFC were found, whereas serum antibody titres were highest. The antibody from immunized trout showed little or no cross-reactions with sheep red blood cells passively labelled With antigens from other fish pathogens.